Viessmann VITODENS 200-W Technical Manual page 71

Design information
(cont.)
Cold water installation, separate DHW cylinder and primary store of the Vitodens 222-W
Example:
DHW cylinder installed below (120 or 150 l) with safety assembly to
DIN 1988
B
C
P
A
E
A Domestic hot water
B Safety valve (included in the standard delivery of the installation
aid for the Vitodens 222-W)
C Visible blow-off line outlet
D Cold water
E Drain
F Shut-off valve
G Flow regulating valve (installation recommended)
Safety valve
The safety valve must be installed.
Drinking water filter
According to DIN 1988-2, a drinking water filter should be installed in
systems with metal pipework. Viessmann also recommends the instal-
lation of a drinking water filter when using plastic pipes, as per DIN
1988, to prevent contaminants entering the DHW system.
DHW circulation (only in conjunction with the Vitodens 200-W and 300-W)
DHW circulation pipes increase DHW convenience and reduce water
consumption. These advantages result from the immediate availability
of hot water at the tap/draw-off point.
However, poor insulation of the DHW circulation line can lead to sub-
stantial heat losses.
From a line length of 7 m and longer, we recommend the installation
of a DHW circulation line with appropriate thermal insulation in accord-
ance with the Energy Savings Order [Germany]. This specifies that the
DHW circulation line should include a circulation pump, a check valve
and a time switch for shutting down DHW circulation during the
night.
VITODENS
O
F G H KE F
D
Safety assembly to DIN 1988
H Pressure gauge connector
K Non-return valve
L Drinking water filter
M Pressure reducer to DIN 1988-2, issue Dec. 1988
N Non-return valve/pipe separator
O Standard delivery of the safety assembly offered as an accessory
P Diaphragm expansion vessel, suitable for drinking water
We recommend you install the safety valve higher than the top edge
of the cylinder. This protects the valve against contamination, scaling
and high temperatures. The DHW cylinder does not then need to be
drained when working on the safety valve.
F E L M F N D
(for separate DHW cylinders only)
6
VIESMANN
71